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package org.hsqldb.lib;

Implementation of an ordered Set which maintains the inserted order of
elements and allows access by index. Iterators return the
elements in the index order.
This class does not store null elements.
Author:
Fred Toussi (fredt@users dot sourceforge.net)
Version:
2.3.3
Since:
1.9.0/**
 * Implementation of an ordered Set which maintains the inserted order of
 * elements and allows access by index. Iterators return the
 * elements in the index order.
 *
 * This class does not store null elements.
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.3.3
 * @since 1.9.0
 */
public class OrderedHashSet extends HashSet implements HsqlList, Set {

    public OrderedHashSet() {

        super(8);

        isList = true;
    }

    public boolean remove(Object key) {
        return super.removeObject(key, true) != null;
    }

    public Object remove(int index) throws IndexOutOfBoundsException {

        checkRange(index);

        return super.removeObject(objectKeyTable[index], true);
    }

    public boolean insert(int index,
                          Object key) throws IndexOutOfBoundsException {

        if (index < 0 || index > size()) {
            throw new IndexOutOfBoundsException();
        }

        if (contains(key)) {
            return false;
        }

        if (index == size()) {
            return add(key);
        }

        Object[] array = new Object[size()];

        toArray(array);
        super.clear();

        for (int i = 0; i < index; i++) {
            add(array[i]);
        }

        add(key);

        for (int i = index; i < array.length; i++) {
            add(array[i]);
        }

        return true;
    }

    public Object set(int index, Object key) throws IndexOutOfBoundsException {
        throw new IndexOutOfBoundsException();
    }

    public void add(int index, Object key) throws IndexOutOfBoundsException {
        throw new IndexOutOfBoundsException();
    }

    public Object get(int index) throws IndexOutOfBoundsException {

        checkRange(index);

        return objectKeyTable[index];
    }

    public void toArray(Object[] array) {
        System.arraycopy(super.objectKeyTable, 0, array, 0, array.length);
    }

    public void addAll(OrderedHashSet other) {

        for (int i = 0, size = other.size(); i < size; i++) {
            add(other.get(i));
        }
    }

    public int getIndex(Object key) {
        return getLookup(key, key.hashCode());
    }

    public int getLargestIndex(OrderedHashSet other) {

        int max = -1;

        for (int i = 0, size = other.size(); i < size; i++) {
            int index = getIndex(other.get(i));

            if (index > max) {
                max = index;
            }
        }

        return max;
    }

    public int getSmallestIndex(OrderedHashSet other) {

        int min = -1;

        for (int i = 0, size = other.size(); i < size; i++) {
            int index = getIndex(other.get(i));

            if (index != -1) {
                if (min == -1 || index < min) {
                    min = index;
                }
            }
        }

        return min;
    }

    public int getCommonElementCount(Set other) {

        int count = 0;

        for (int i = 0, size = size(); i < size; i++) {
            if (other.contains(objectKeyTable[i])) {
                count++;
            }
        }

        return count;
    }

    public static OrderedHashSet addAll(OrderedHashSet first,
                                        OrderedHashSet second) {

        if (second == null) {
            return first;
        }

        if (first == null) {
            first = new OrderedHashSet();
        }

        first.addAll(second);

        return first;
    }

    public static OrderedHashSet add(OrderedHashSet first, Object value) {

        if (value == null) {
            return first;
        }

        if (first == null) {
            first = new OrderedHashSet();
        }

        first.add(value);

        return first;
    }

    private void checkRange(int i) {

        if (i < 0 || i >= size()) {
            throw new IndexOutOfBoundsException();
        }
    }
}